Vibration detection apparatus, hologram apparatus, vibration detection method for the vibration detection apparatus, and recording method for the hologram apparatus

摘要

A hologram apparatus comprises a vibration detection beam generation unit to apply a vibration detection beam, incoherent to the data and reference beams and to detect the presence/absence of vibrations, to the hologram recording medium; a light reception/determination unit to receive the vibration detection beam emitted from the medium after the beam is applied to and propagates through the medium and to determine whether the beam receiving position is within a preset range; and an interruption unit to interrupt at least one of the data and reference beams from being applied to the medium, when this unit has determined that the position of beam reception is not within the preset range.